1. Field of the Invention
The invention relates to the manufacture, preparation and treatment of flat objects, such as silicon wafers, under a special, ultraclean atmosphere. The silicon wafers in question are used for the manufacture of integrated circuits in the electronics and microelectronics field. Other applications can be envisaged, particularly under a vacuum.
2. Description of Related Art
The manufacture of electronic circuits on circular silicon wafers requires the latter to be treated under a special atmosphere and handled and stored under an ultraclean atmosphere, i.e. surrounded by controlled nitrogen or highly pure air. Up to now several system concepts have been used.
A first concept consists of placing the room where the silicon wafers are treated under the ultraclean atmosphere in question, i.e. under a controlled atmosphere. This leads to large air filtration/ventilation installations and sophisticated clothing for each operator working in the room.
Another concept consists of placing under the controlled atmosphere only the points at which the silicon wafers are stored and handled. These are the working stations and storage containers. The transportation of the wafers from one working station to another or from a storage station to a working station takes place by means of containers equipped with cassettes or cases having a shelf system able to receive between ten and thirty superimposed silicon wafers. These generally tight containers can even be equipped with their own ultraclean air supply system.
The aim of the invention is to propose another silicon wafer handling system concept. With regards to the fragility and treatment conditions, these silicon wafers can be likened to digital optical disks and to compact audiodigital disks.